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Sunset!

So what’s the first thing that comes to mind when you think of a sunset? A kaleidoscope of colors, a glassy smooth lake, crashing surf, the soft warm glow over a cityscape, or mountain peaks bathed in pink light? How about all of the above? Well I do too, and for that very reason I wanted to shoot something different for the weekly theme as I’m trying to use the weekly themes to challenge me in my photography to think outside the obvious (I don’t always succeed, and sometimes I just want the obvious shot because I’m lazy)  Here are some of the shots others in the group made for this theme. Another reason to think outside the box for this theme is that my work schedule really only leaves me one day of the week to catch a sunset and even then I’m usually busy doing other things, or I’m just dead tired and don’t want to do anything at all…

So how do you shoot a sunset when the Suns already down? Take it off planet baby…

The Sun slowly sets over Mare Imbrium during Last Quarter Moon September 8, 2012. Afocal shot using a 50mm f/1.8 +12mm extension tube and a 40mm 2″ eyepiece on a Meade 10″ LX-50 SCT Telescope.

At this point I should probably explain some astrophotography terms:

T-Adapter: A small tube that screws onto the visual back of the telescope and attaches to your camera via a T-Ring (has a camera mount identical to the back of a lens) This has no lens elements and is very similar to an extension tube (but has no contacts or focusing tab)

Prime Focus: When the camera is attached directly to the telescopes optical path, using the T-Adapter and T-ring. Basically the telescope becomes a large, heavy,unwieldy, and in the case of my particular telescope an f/10 or f/6.3 telephoto lens for the camera.

Afocal: Using a camera with a lens and shooting into the eyepiece of the telescope (good for Point & Shoot cameras and phones) or for getting closer as the eyepiece magnifies the view drastically.

Focal Reducer: A lens that reduces the native focal length/aperture (telescopes use those terms differently then cameras) from an f/10 or ‘slow’ telescope to a ‘fast’ f/6.3 which also increases the visual field of view and is necessary to fit the entire Lunar disk into the frame of a DX/crop sensor camera at Prime Focus.

As the Moon began to rise over the distant mountains I started shooting using Live View to help me focus, which next to tracking is the hardest part of astrophotography for me. I would max zoom the live view and slowly try to find the best focus, then using mirror lock up (remember to let the scope settle for a few seconds after locking the mirror up!) I would trigger the shutter with a wireless remote. I started out using the focal reducer to let me shoot the entire Lunar disk in one shot, but then I removed it and shot at Prime focus to get more detail and decided I would just stitch the images together as it only takes two shots to see the entire disk as it just barely doesn’t fit, a full frame camera has no problem fitting the entire Moon into the frame.

Here’s that image:

Last Quarter Moon at Prime Focus
A stitched image made from 7 exposures. (I only needed two, but went overboard to get the sharpest results I could)

I’m getting that one printed large!

Can I mention how much I love digital over film? I never got that good an image out of my OM-1 and film on this same telescope, and I attribute it all to the great sensor on the D7000 and post processing.

To get closer though I need to magnify the view, now I could just crop, but that cuts resolution and the final size I could print. This is where you begin to add other lenses to the Telescope-Camera optical path by means of an eyepiece projector (a longer T- Adapter that holds an eyepiece and then attaches to the camera) By using various eyepieces you can change the magnification of the view. I didn’t have my eyepiece projector with me and I didn’t feel like running inside to grab it so instead I put a 12mm extension tube on the 50mm f/1.8 and handheld it up to a 40mm eyepiece and shot afocally to give me the closer view.

Mare Imbrium and the bright crater Copernicus
50mm with 12mm extension tube afocal shot with 40mm eyepiece on a 10″ LX-50 SCT.

The D7000 attached at the Prime Focus of the LX-50

I took off my battery grip to lighten the weight my scope had to carry although I have counterweights if I want to leave it on.

The night sky as I finished shooting. Notice the haze and light pollution from the entire Salt Lake Valley. That small dot above the overexposed Moon is Jupiter, and with Orion underneath it means that winter is on its way. 

As the night wore on Jupiter and the Moon slowly crept closer and closer to each other and just before I called it quits I was able to get them into one frame together using the f/6.3 reducer and using that as a guide to their relative positions I stitched together a pano I made of the Moon and Jupiter both shot at Prime Focus to give you a sense of scale and distance.

That little dot upper center is the giant gas giant Jupiter with a circumference of 44,423 miles it is the largest of all the planets in our Solar System, and at our closest to each other Jupiter is a staggering 390,682,810 miles away!

Compare that to the Moon which is much smaller with a circumference of only 6,785 miles but at its closest is a paltry 221,457 miles away. So here’s a perfect example of the subject – distance relationship. 🙂

Thanks for taking this little space ride with me! Next week is another of my favorite pastimes – Football!

Happy Shooting!

Howard

 

 

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